The invention has to do with an insertion system for use in entering the lumen of a blood vessel, to insert and replace treatment instruments.
Usually the Seldinger Technique is used for inserting catheters into blood vessels. By this means, an access called a hemostatic inserter projects out of the body surface. Its central opening is closed to begin with in self-acting fashion by means of a plug, made of soft elastic material in the shape of a star. Through this opening, the front end of a guide catheter is then extended into the lumen of the blood vessel until the tip of the guide catheter gets as close as possible to the treatment site with the actual treatment catheters or instruments. The back end of the guide catheter then lies outside the opening of the hemostatic inserter. An access is attached on this end of the guide catheter, to be closed by such means as a screw cap and to be opened partially or fully. This access is designated as an insertion valve.
The insertion valve is configured according to the packing box principle, and has a soft elastic, cylindrical sealing ring with a central opening. This sealing ring, depending on the desired sealing action or residual opening to be adjusted, is shape-adapted using an axially displaceable piston ring by compressing together.
One example of a task is to carry out coronary vessel dilation using a balloon dilation catheter, The task is to insert the guide wire and then the treatment catheter with its particular relatively sensitive tip into the lumen of the blood vessel so that it will not be damaged, and advance it to the location to be treated. To accomplish this, the access opening of the insertion valve must as a rule, be completely open. During the period until it can again be closed so that the guide wire or treatment catheter is tightly enclosed, but may simultaneously be able to be shifted longitudinally, several milliliters of surrounding blood of necessity is expelled.
As with the previously described insertion of the guide wire and the treatment catheter, these particulars essentially, including expelling of blood, are repeated in all additional measures for replacing the catheter, since the insertion valve must in each instance be opened for at least a few seconds. Overall blood loss in the course of such a treatment in this way can be considerable, especially in patients with high blood pressure. Contamination of the insertion valve""s vicinity by blood has been assumed until now to be an unavoidable annoyance. Blood loss, if they are aware of it, can be perceived by patients to be psychologically stressful.
The invention solves the problem by improving and supplementing previous insertion systems so that all outflow of blood is avoided when using them.
The lockable insertion opening of the insertion valve with its sealing ring and the shutoff device somewhat carry out the function of two lock gates at the ends of a lock chamber in a channel which extends from the sealing ring into the lumen of the guide catheter. These functions can be taken over by the sealing ring and the shutoff device, if a guide wire is in the channel.
The invention-specific shutoff device, if brought into the closed setting, makes it possible at, at any time, to open the insertion valve without having blood come out of its central insertion opening. First, the guide wire, and next the catheter head, in the case, for example, of a balloon dilation catheter, with its tip and the dilation balloon, and at least one short part of the immediately adjoining catheter shaft, is pushed through the opened sealing ring of the insertion valve. As soon as this is done, the sealing ring, and thus its central insertion opening, without force or hurried activation, can be adapted to the diameter of the guide wire or of the catheter shaft. On the one hand, this achieves the necessary sealing action, and on the other, it permits the guide wire or catheter shaft to be moved longitudinally. If necessary, the guide wire which is laid before insertion of the catheter to the treatment site is held by the closed shutoff device, and is thus secured against being shifted longitudinally. By this means, the head of a following treatment catheter can be shifted from the end of the guide wire that lies outside, onto the guide wire, without this having to be separately held securely. After these steps, the shutoff device can be opened and the catheter head can be shifted in the direction of the treatment site.
DE-Cl-33 24 699 makes known a valve device in an aspirating set for carrying out central venous puncture, in the shape of a hose piece. Its internal cross section can be closed by twisting.
From EP-A2-0 546 712, a valve device for a so-called over-the-needle-in catheter, i.e., a short catheter is known which is to be placed as an access to a blood vessel by means of a puncture needed with its tip projecting out over its distal end. By means of a correcting element, the short catheter can be locked by pinching off at its proximal end.
Neither device makes provision, however, to create a lock chamber in the access area to the catheter by two lock gates, as is the case with the present invention.
One advantageous embodiment shape of an insertion system with the invention-specific shutoff device is characterized in having a side channel that empties at a suitable location, preferably in the area of the shutoff device, into the main channel. Through this side channel, a sterile, clear liquid, preferably physiological saline solution, can be injected into the lumen of the main channel between the emptying location and the sealing ring of the insertion valve. Use of a clear wall material in manufacturing at least the main channel between the shutoff device and the sealing ring makes it possible to observe the position of each catheter head during the insertion process. In other respects, the liquid is prevented from coming out of the insertion valve just as blood otherwise is. The liquid represents a xe2x80x9cclean additive stopperxe2x80x9d of the system. As a further improvement, an additional side channel is provided, for example as close as possible to the sealing ring, via which the liquid can be injected or changed without even partial opening of the insertion valve, if it should gradually become mixed with blood due to longitudinal shifting of the treatment catheter.
For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings.